Due to item 1, adding an ADU can require years to start achieving any return (once the accumulated cash flow recovers the initial negative position).4) Adding an ADU is a slow process.

My first and foremost question is where to start?

Starting your a property management company is not simple. 

I used to work for a start up, we sold maintenance software to big oil and gas, chemical companies and other big producers.

I have had this issue on occasion and after verifying it with the HVAC company - let them know that AC's are only built to reduce temperature by 20 or so degrees.

I gave a low ball offer to start (35K below asking price, which was rejected). 

In the middle of a sale of my parents condo and it's been 5 months and we have not closed due to title companie's lack of communication, instruction and then bringing an outside attorney into the fold to assist that has dragged this on even further.

The biggest thing we started doing after our first 2-3 flips is focusing on the higher-roi aspects such as kitchens and baths, and then doing "just enough" for everything else. 

I'd get started sending this guy packing.

I did 12 years, got out last year, and started a defense consulting firm.